Transactions are frequently conducted using portable devices, for example payment cards. Such portable devices are often capable of interacting via both contact and contactless connections. An example of a contact interaction is a “chip and PIN” interaction according to the EMV (Europay, MasterCard, Visa) standard, which describes smart cards which store and process data in integrated circuits. In a “chip and PIN” interaction, the card is inserted into a reader, for example in a point of sale terminal, which reads card data via contacts on the surface of the card, and the user authenticates their identity by providing a PIN. In a contactless interaction, data is transmitted from a chip of the card to a reader using short-range radio transmissions. An example of a chip for contactless interactions is a MIFARE chip, for example MIFARE DESFire, supplied by NXP Semiconductors.
The capacity for contact and contactless transactions may be combined in a single “dual application” card. These typically require contact transactions to be processed by one application on the card, and contactless transactions to be processed by a different application, with minimal intra-card communication between the two applications. An interaction requiring both applications would thus require the user to alternate between contact and contactless interactions.